fabs, floor, ceil, fmod, rint - absolute value, floor, ceiling, float‐
ing point remainder, and round-to-nearest functions
double fmod (x, y)
double x, y;
The routine returns the absolute value |x|.
The routine returns the largest integer no greater than x.
The routine returns the smallest integer no less than x.
The routine returns the floating point remainder of the division of x
by y: zero if y is zero or if x/y would overflow; otherwise the number
f with the same sign as x, such that x = iy + f for some integer i, and
|f| < |y|.
The routine returns the integer (represented as a double precision num‐
ber) nearest x in the direction of the prevailing rounding mode.
See Alsoabs(3), intro(3m)